I do agree that WRC 107 is used to determine stress induced in shell (cylindrical / spherical) due to force & moment imposed by attachment (cylindrical / rectangular, hollow / solid).

But output of PVElite mention below:

Input Echo, WRC107/537 Item 1, Description: VC-PP-10 :
Diameter Basis for Vessel Vbasis ID
Cylindrical or Spherical Vessel Cylsph Cylindrical
Internal Corrosion Allowance Cas 6.0000 mm
Vessel Diameter Dv 1100.000 mm
Vessel Thickness Tv 28.000 mm
Design Temperature 66.00 °C
Vessel Material SA-516 70
Vessel Cold S.I. Allowable Smc 1407.10 kgf/cm²
Vessel Hot S.I. Allowable Smh 1407.10 kgf/cm²

Attachment Type Type Round
Diameter Basis for Nozzle Nbasis OD
Corrosion Allowance for Nozzle Can 0.0000 mm
Nozzle Diameter Dn 219.100 mm
Nozzle Thickness Tn 8.180 mm
Nozzle Cold S.I. Allowable SNmc 1407.10 kgf/cm²
Nozzle Hot S.I. Allowable SNmh 1407.10 kgf/cm²


and output of CodeCalc mention below:

Input Echo, 107/537 Item 10, Description: VC-PP-10
Diameter Basis for Vessel Vbasis ID
Cylindrical or Spherical Vessel Cylsph Cylindrical
Internal Corrosion Allowance Cas 6.0000 mm
Vessel Diameter Dv 1100.000 mm
Vessel Thickness Tv 28.000 mm
Design Temperature 66.00 C
Vessel Material SA-516 70
Vessel UNS Number K02700
Vessel Cold S.I. Allowable Smc 1406.14 kgf/cm^2
Vessel Hot S.I. Allowable Smh 1406.14 kgf/cm^2

Attachment Type Type Round
Diameter Basis for Nozzle Nbasis OD
Corrosion Allowance for Nozzle Can 0.0000 mm
Nozzle Diameter Dn 219.100 mm
Nozzle Thickness Tn 8.180 mm
Nozzle Material SA-106 B
Nozzle UNS Number K03006
Nozzle Cold S.I. Allowable SNmc 1202.25 kgf/cm^2
Nozzle Hot S.I. Allowable SNmh 1202.25 kgf/cm^2


WRC 107 Interface in Codecalc is similar to nozzle attachment thus material & allowable stress are mention in output.

But in PVElite material selection is not possible for clip. though clip material is indicative but correct material need to be mention in output.